BACKGROUND: Irritable bowel syndrome (IBS) is the most common disorder seen by gastroenterologists. Recently, attention has focused upon better elucidation of the burden of illness of IBS. An understanding of the burden of illness is fundamental to making an assessment of the riskbenefit relationship for existing therapies, as well as for agents in development.
OBJECTIVES: The objective was to determine the prevalence, demographics, burden of illness, and resource use among participants who met the symptom criteria for IBS using a novel, web-based survey in a large U.S. population-based sample.
METHODS: A sample of 31,289 participants was drawn from an online, web-based research panel (surveyed December 2001 to February 2002) consisting of over 150,000 household members. Probability sampling techniques and stratified, random-digit dialing were used to recruit the sample. All participants received a screener for symptoms of IBS per the Rome II criteria. For individuals satisfying the Rome II criteria for either diarrhea-predominant (dIBS) or alternating IBS (aIBS), a second questionnaire addressing demographics, prior medical care utilization, and symptoms was administered. Key measures included prevalence rates, demographic characteristics, health care utilization, and quality of life (SF-36).
RESULTS: Of the participants who received the screener, 25,986 (82%) completed it and 1,713 fulfilled the Rome II criteria for IBS; prevalence rate of 6.6% (CI: 6.3,6.9). In total, 901 individuals had dIBS (prevalence 3.5%; CI: 3.3,3.7 – females 4.1%, males 2.7%) and 453 had aIBS (prevalence 2.7%; CI: 1.5,1.9 – females 2.3%, males 1.2%). Participants with dIBS or aIBS averaged 44 years of age and were more often white, female, and employed with at least some college education. Fifty-one (51%) percent of participants had seen their physicians within the past 12 months for their IBS and most had used a therapeutic agent within the past 12 months for treatment of the symptoms. As compared to U.S. norms, participants’ quality of life was markedly affected by IBS.
CONCLUSIONS: Data from population-based samples using symptom criteria for IBS can be rapidly collected through web-based surveys. The results of this large, population-based study confirm the high prevalence and burden of illness of IBS. These data are an important component of risk-benefit assessment.
